import {runInOp} from "../display/operations.js"
import {ensureCursorVisible} from "../display/scrolling.js"
import {Pos} from "../line/pos.js"
import {getLine} from "../line/utils_line.js"
import {makeChange} from "../model/changes.js"
import {ios, webkit} from "../util/browser.js"
import {elt} from "../util/dom.js"
import {lst, map} from "../util/misc.js"
import {signalLater} from "../util/operation_group.js"
import {splitLinesAuto} from "../util/feature_detection.js"

import {indentLine} from "./indent.js"

// This will be set to a {lineWise: bool, text: [string]} object, so
// that, when pasting, we know what kind of selections the copied
// text was made out of.
export let lastCopied = null

export function setLastCopied(newLastCopied) {
    lastCopied = newLastCopied
}

export function applyTextInput(cm, inserted, deleted, sel, origin) {
    let doc = cm.doc
    cm.display.shift = false
    if (!sel) sel = doc.sel

    let recent = +new Date - 200
    let paste = origin == "paste" || cm.state.pasteIncoming > recent
    let textLines = splitLinesAuto(inserted), multiPaste = null
    // When pasting N lines into N selections, insert one line per selection
    if (paste && sel.ranges.length > 1) {
        if (lastCopied && lastCopied.text.join("\n") == inserted) {
            if (sel.ranges.length % lastCopied.text.length == 0) {
                multiPaste = []
                for (let i = 0; i < lastCopied.text.length; i++)
                    multiPaste.push(doc.splitLines(lastCopied.text[i]))
            }
        } else if (textLines.length == sel.ranges.length && cm.options.pasteLinesPerSelection) {
            multiPaste = map(textLines, l => [l])
        }
    }

    let updateInput = cm.curOp.updateInput
    // Normal behavior is to insert the new text into every selection
    for (let i = sel.ranges.length - 1; i >= 0; i--) {
        let range = sel.ranges[i]
        let from = range.from(), to = range.to()
        if (range.empty()) {
            if (deleted && deleted > 0) // Handle deletion
                from = Pos(from.line, from.ch - deleted)
            else if (cm.state.overwrite && !paste) // Handle overwrite
                to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length))
            else if (paste && lastCopied && lastCopied.lineWise && lastCopied.text.join("\n") == inserted)
                from = to = Pos(from.line, 0)
        }
        let changeEvent = {
            from: from, to: to, text: multiPaste ? multiPaste[i % multiPaste.length] : textLines,
            origin: origin || (paste ? "paste" : cm.state.cutIncoming > recent ? "cut" : "+input")
        }
        makeChange(cm.doc, changeEvent)
        signalLater(cm, "inputRead", cm, changeEvent)
    }
    if (inserted && !paste)
        triggerElectric(cm, inserted)

    ensureCursorVisible(cm)
    if (cm.curOp.updateInput < 2) cm.curOp.updateInput = updateInput
    cm.curOp.typing = true
    cm.state.pasteIncoming = cm.state.cutIncoming = -1
}

export function handlePaste(e, cm) {
    let pasted = e.clipboardData && e.clipboardData.getData("Text")
    if (pasted) {
        e.preventDefault()
        if (!cm.isReadOnly() && !cm.options.disableInput)
            runInOp(cm, () => applyTextInput(cm, pasted, 0, null, "paste"))
        return true
    }
}

export function triggerElectric(cm, inserted) {
    // When an 'electric' character is inserted, immediately trigger a reindent
    if (!cm.options.electricChars || !cm.options.smartIndent) return
    let sel = cm.doc.sel

    for (let i = sel.ranges.length - 1; i >= 0; i--) {
        let range = sel.ranges[i]
        if (range.head.ch > 100 || (i && sel.ranges[i - 1].head.line == range.head.line)) continue
        let mode = cm.getModeAt(range.head)
        let indented = false
        if (mode.electricChars) {
            for (let j = 0; j < mode.electricChars.length; j++)
                if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {
                    indented = indentLine(cm, range.head.line, "smart")
                    break
                }
        } else if (mode.electricInput) {
            if (mode.electricInput.test(getLine(cm.doc, range.head.line).text.slice(0, range.head.ch)))
                indented = indentLine(cm, range.head.line, "smart")
        }
        if (indented) signalLater(cm, "electricInput", cm, range.head.line)
    }
}

export function copyableRanges(cm) {
    let text = [], ranges = []
    for (let i = 0; i < cm.doc.sel.ranges.length; i++) {
        let line = cm.doc.sel.ranges[i].head.line
        let lineRange = {anchor: Pos(line, 0), head: Pos(line + 1, 0)}
        ranges.push(lineRange)
        text.push(cm.getRange(lineRange.anchor, lineRange.head))
    }
    return {text: text, ranges: ranges}
}

export function disableBrowserMagic(field, spellcheck, autocorrect, autocapitalize) {
    field.setAttribute("autocorrect", autocorrect ? "" : "off")
    field.setAttribute("autocapitalize", autocapitalize ? "" : "off")
    field.setAttribute("spellcheck", !!spellcheck)
}

export function hiddenTextarea() {
    let te = elt("textarea", null, null, "position: absolute; bottom: -1em; padding: 0; width: 1px; height: 1em; outline: none")
    let div = elt("div", [te], null, "overflow: hidden; position: relative; width: 3px; height: 0px;")
    // The textarea is kept positioned near the cursor to prevent the
    // fact that it'll be scrolled into view on input from scrolling
    // our fake cursor out of view. On webkit, when wrap=off, paste is
    // very slow. So make the area wide instead.
    if (webkit) te.style.width = "1000px"
    else te.setAttribute("wrap", "off")
    // If border: 0; -- iOS fails to open keyboard (issue #1287)
    if (ios) te.style.border = "1px solid black"
    disableBrowserMagic(te)
    return div
}
